LCML - CW laser source using measurement data | lcml_ld_cw_1550_measured

laser
lcml

#1

This continuous wave (CW) laser model is built based on measurement data. This model has an electrical input/output port for the driving signal.

Example Test File

ld_cw_measured.icp (308.9 KB)

User Guide

lcml_ld_cw_1550_measured (ld)

LCML: CW laser with electrical input/output, based on experimental data.

Ports

Name Type
ele_1 Electrical Signal
opt_1 Optical Signal

CML/Laser

Name Default value Default unit Range
frequency 193.1 THz*
*std. unit is Hz
[1e-112, 1e+88]
LI_curve C:/Users/LCML/library/LCML_v4/lib_data/laser/LI_mA.txt -- --
VI_curve C:/Users/LCML/library/LCML_v4/lib_data/laser/VI_mA.txt -- --
linewidth 1 MHz*
*std. unit is Hz
[-1e+94, 1e+94]
wavelength
temperature
tunability
0.1 nm/K [-1e+100, 1e+100]
note Electrical input is current, output is voltage. -- --

Model Development

INTERCONNECT
This element allows users to define the laser performance based on measurement data, as listed in the table below.

Name Kind Type Value (default) Unit Category
central_frequency Frequency Number 193.1 THz Laser
LI_curve NonQuantity FileOpen LI_mA.txt Laser
VI_curve NonQuantity FileOpen VI_mA.txt Laser
linewidth Frequency Number 1 MHz Laser
wavelength_temperature_tunability FixedUnit Number 0.1 nm/K Laser

The subcircuit of this compound element is shown below.

The electrical port takes current as input and outputs the corresponding voltage via the Lookup Table element, which defines their relationship by a lookup table file loaded from the “VI_curve” property. Note that a [Port Converter] (https://kb.lumerical.com/en/index.html?ref_primitive_elements_port_converter.html) is introduced to convert the bidirectional electrical port “ele” into one input and one output ports.

The current is also applied onto the Optical Modulator Lookup Table element, which defines the relationship between power and current in another lookup table file loaded from the “LI_curve” file property. This essentially modulates the power from the fixed CW laser source to mimic the actual operation of the laser diode (i.e., a certain injection current generates a certain optical power).

The default LIV data stored in LI_mA.txt and VI_mA.txt are plotted below. Note that in this particular example, the LI and VI data should be in units of mW-A and V-A, respectively. The text files can be found in the LCML_resource folder in the download page.

The setup script of the compound element is written below:

operating_frequency = c/(c/central_frequency+wavelength_temperature_tunability*1e-9*(temperature-300));
setnamed("CWL_1","frequency", operating_frequency);
setnamed("CWL_1","linewidth", linewidth);

setnamed("OM_1","load from file",true);
setnamed("OM_1","filename",LI_curve);
setnamed("CWL_1","enable RIN", false);

setnamed("TABLE_1","load from file",true);
setnamed("TABLE_1","filename",VI_curve);

Test

Download the simulation file ld_cw_measured.icp from the top of this page. In this simulation file, the laser is connected to and measured by an Optical Spectrum Analyzer (OSA) and a Power Meter. The linewidth is set to be 1 MHz and the electrical input is driven by a DC Source in the example file. Click on the “run” button and the OSA will be populated with measurement data. The power spectrum is plotted in the top right corner in the following figure. The sweep object “sweep” defined in the file sweeps through the input current to the laser diode and plots the output power as a result. The sweep result is plotted at the bottom in the following figure, and it shows great agreements with the original measurement data.


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